The present invention relates to an electronically controlled fuel injection device for an internal combustion engine, and more particularly to an electronically controlled gasoline injection device capable of rapidly increasing load at low engine speed in a fuel preference system.
An electronically controlled fuel injector of the fuel preference type (hereinafter referred to as EAC), generally, has a system in which at first the quantity of fuel is determined in accordance with accelerator actuation and then the quantity of air is determined so as to maintain engine operation at an optimum air-fuel ratio. In the EAC system, therefore, since the accelerator pedal stroke (instruction value of engine driving) corresponds to the fuel flow, the stroke is converted into the fuel flow by a certain computer program and the conversion is effected linearly or nonlinearly so that it is possible to obtain different engine responses for an accelerator pedal stroke. FIG. 1 shows one relationship between the accelerator pedal stroke and the fuel flow. In the case of smooth relation as shown in FIG. 1, it is possible to obtain a very suitable feeling with steady speed acceleration and deceleration at light engine load.
However, when it is necessary to increase load rapidly with low engine speed, for example, such as at starting, the magnitude of the accelerator operation becomes large or engine speed, i.e., the rate of engine rotation, becomes low or decreased to the point when a smooth drive feeling cannot be maintained.